Box fuel tank

[Chris H]

Has anyone converted to just a fuel tank in the box and eliminated the saddle tanks? If so what are the requirements or regulations that you needed to install. Or is it even legal to use a tank like that to gravity feed to fuel pump?

 

[AuroraGirl]

If you have a fuel pump it doesnt need to gravity feed. its still gotta pull the gas upward to the carburetor. is there something not working properly? such as lean or no fuel?

 

[gotyourgoat]

You could get a tank from a 67-72 and start cutting the cab up.

Afraid of the lies about the saddle tanks?

 

[Chris H]

Having trouble getting fuel to carb. I think I may have figured something out. Fuel pump doesn't have return line. May get new fuel pump with return line andbhooknthat back up. May be causing to vapor lock.

 

[gotyourgoat]

So the the lines there still there and the pump was replaced with a non return line pump?
Sounds like a oe pump would help you out.

To gravity feed fuel the tank would have to be on a tower a couple feet above the cab. If that would even work.

 

[AuroraGirl]

So the the lines there still there and the pump was replaced with a non return line pump?
Sounds like a oe pump would help you out.

To gravity feed fuel the tank would have to be on a tower a couple feet above the cab. If that would even work.

I dont think pressure from gravity could maintain it at the carb, because it needs pressure which would be constantly varying with percentage

 

[Chris H]

Yeah, I just ordered me a replacement pump with the return feed off of it. Gravity feed would be to an electric pump that would be supplying fuel to the carburetor. But this is a lot easier and cheaper way to go if this works, which I think it will. I think it's been Vapor locking because the return system is plugged off.

 

[Craig 85]

Check the condition of your rubber fuel lines. Maybe they are soft and collapsing. Remember to check the ones at the tank too.

You must be registered for see images attach

 

[gotyourgoat]

I dont think pressure from gravity could maintain it at the carb, because it needs pressure which would be constantly varying with percentage

Huh?

 

[WebMonkey]

Huh?

the term 'gravity feed' got tossed out there and some were thinking TOTAL gravity feed to the carb and some were understanding gravity out of the fuel tank into a pump and then onto the carb.

 

[WebMonkey]

Check the condition of your rubber fuel lines. Maybe they are soft and collapsing. Remember to check the ones at the tank too.

You must be registered for see images attach

en-VEE-us

sweet!

 

[Markmx6]

If the vehicle is supposed to have a return line and it is blocked off it will try and pull a vacuum on the tank. You could always leave the gas cap off and see if your problem goes away, just to make sure.

Funny story though. I used to work for an emissions shop and a camaro came in and it failed on the evaporative system, it wouldn't hold pressure. So another mechanic put a couple BB's in the evap hose by the canister. It fools the test enough to pass and then you pull the BB's out after the test. Anyway, he didn't come back after testing until the car kept running out of gas, but the gauge showed full.

I put the car on a lift and the tank had collapsed from the vacuum of the electric fuel pump and it wedged the arm for the tank level sensor to the top of the tank making it show full. It only held like 5 gallons of fuel at that point.

We made a gas cap with a regulator and a compressor fitting and pushed it to about 50 PSI to get the tank back in shape. Luckily that also provided a good leak test and nothing had creased or cracked. Then we pulled the BB's...

Ok reading that doesn't seem as funny, but it was seeing it...

 

[Grit dog]

Or is it even legal to use a tank like that to gravity feed to fuel pump?

Separate from the mis-construed responses, from my experience it is not legal to have an aftermarket gasoline "transfer" tank that directly feeds the OE tanks or the fuel system directly.
And there's only a handful of transfer tanks that are DOT rated to haul gasoline. But this is from DOT regs and research years ago, although I doubt the rules are more lax now.

Best off to fix the issue properly, like you are, IMO.

 

[Nuckollsr]

My 87 R1500 has TBI injection and saddle tanks along with a very busy valve with 6 hoses and 5 wires. I recently replaced both tanks (badly rusted and one with bad pump). This system runs about 10 psi fuel pressure to a pressure relief valve at the carb with a return line that takes overflow back to the active tank. Without that return line (1) the pressure relief valve cannot provide uniform pressure at the injectors and (2) there is no continuous flow of fuel in the plumbing hence no cooling and vapor lock prevention. Ya gotta have that return line.

I eliminated the tank selector valve by simply plumbing both pumps to the carb through check valves. Either pump can supply the engine depending on which one has power. Return line is permanently plumbed to the right tank. The switch on the dash directly selects which pump is powered and which sender drives the gage. I run the right tank until dry. Switch to the left tank and run it until dry, then go back to right tank to find that the return line has partially refilled the tank. At that point, ALL REMAINING FUEL is in the right tank and fully accessible to the engine. That tangle of hoses and wires goes away.

I'll upload a drawing of the mod. Don't know if it's applicable to your engine/carb configuration but it sure works nice with the '87 TBI